3 months in - think I know what I like now.. and looking for advice

[powerlord]

So, equipment in sig. Warning: it's a long one...

Friday night I got my asiair pro set up with my 72ED and modded Canon 6d. The mount is an EQ5, with an EQStarPro controller and belt driven servos.

I was guding with my ASI224.

My target was M51 - if was gonna be small, but I wanted to see a galaxy!! 😀

The result was ok, about what I could expect - with a nearly full moon, 37 lights 90 seconds, iso1600, and nowt else.

And heck, it was the first galaxy I've ever seen !! (andromeda not visible from garden)

Last night, I was back again with better PA (took me 20 mins as the EQ5 tilt is quite worn and it was back and forward, back and forward.. but with a larger guide scope (50mm vs 30mm), and my Mak 102 with the 6D.

I spent about 2 hours setting up, and trying to get the guiding tuned, and mostly I was getting RMS error of less that 2 degrees, with most of that being DEC (I assume my PA wasn't as good as I thought). I shot 60 lights at 180 seconds iso1600. I shot darks, flats and bias.

Sometimes DEC was really struggling, so only 43 were good.

There is a fair bit more detail in there, but not as much as I hoped.

Am I expecting too much do you think and this is about as good as I can get with my current kit ?

I feel that my old EQ5 might just not be up to small targets like this - I do want to try my AZ GTI just to see how it compares.. but I imagine if the EQ5 setup is struggling the AZ GTI will certainly struggle.

I came into the hobby wanting to basically try a bit of everything and then see what I like best.

I originally thought going down to complex laptop, guiding, modded dslrs, etc direction was not for me and i wanted simplicity.

However as a super-nerd, I should have known better.

What I reckon I'd enjoy best, is a solid setup that will me shoot nebulas and galaxies. The odd planet would be good, but I think I'd like to focus on nebulas and galaxies - moving into mono, narrowband, hubble pallete, etc.

So.. rather than add more and more not quite right equipment to the already burgeoning pile I have accumulated in 3 months, I think maybe now is the time to flog what doesn't meet those goals, and get the kit I do need to do it well:

- two setups: one mobile(ish) that I can take with me in the motorhome, probably built around the az gti in eq mode, and one for the garden for the serious stuff.

Serious mount wise, seems to me it's a no brainer to get an EQ6-R PRO ? Ticks all the boxes ?

After that though I'm a bit lost.

Imaging wise, unless I do narrowband with colour camera (many doing? worthwhile ? not trying to win competitions, but do wanna get cool shots ), i suppose im looking at mono camera, filter wheel and LRGB, Ha,Oiii,Sii ?

What do you think are the best options ? 1600GT ?  1600 pro mini ? or colour like ASI294 ?

But it's when I get to OTAs I'm really lost. I think the 72ED I have is a keeper - it's ideal for most nebula - AND it's portable for the motorhome ?

So if thats the case, could I cover the rest (smaller nebula, galaxies) with one other OTA ? Are we talking something expensive around the 200-2500mm range ? EDGE HD or summit ?

I know I'm very much running before I can walk, but I like progressing fast, and I feel at the moment, I might have outgrown the skymax 102, I've yet to actually use the 200p I got hold of, basically because it's really too big/heavy for the EQ5/EQStarPro and the one time I tried it, it was just so so cumbersome to try and use.. And though I've enjoyed using my Canon's, I wonder if know, I'm trying to knock a square peg in a round hole, and should sell them on (well maybe keep the 6d).

EDIT: got a bit carried away there - the point I was also gonna make was - do I just need a different OTA for small stuff and that would let me get nice pics with my 6d ? I mean, I can still shoot narrowband, etc. ?

stu

Friday night with the 72ED:

 

Saturday night with the Mak102:

 

[Clarkey]

Sounds like you have the gear for a lightweight set up and widefield with the 72 ED and the AZ GTi. The 200P would be quite capable of imaging galaxies whether with a DSLR or Astro camera. I think your real shortcoming is with the mount. The EQ5 is going to struggle with anything larger than the 72. An HEQ5 is a reasonable mount but with the 200P or something similar it would be at its limit. Any wind or balance issues would make it tricky. If I was in you position the mount is the first thing I would look at - probably a NEQ6 or similar size. This can be used with all your existing kit and will really help with the guiding and longer FL scopes. (I use an AZ-EQ6 with a 1600mm RC and it is fine, typically I get around 0.3 RMS). Moving on with mono / NB can always be an option later - but I think you can get some really good images with the DSLR first.

[powerlord]

thanks, neq6, eq6-r, az-eq6:

as faras i can tell.. neq6 is decent gear driven, az-gt6 same but with az option, and eq6-r is belt driven?\

eq6-r most accurate ? but other 2 prob good enough ?

[The Lazy Astronomer]

2 hours ago, powerlord said:

thanks, neq6, eq6-r, az-eq6:

as faras i can tell.. neq6 is decent gear driven, az-gt6 same but with az option, and eq6-r is belt driven?\

eq6-r most accurate ? but other 2 prob good enough ?

Pretty sure both the az-eq6 gt and the eq6r pro are belt driven. Go for the latter unless you particularly value the option of using the alt az mode for visual. In my opinion there's no mount that beats an eq6r pro in its price range.

That big newt should be pretty good for galaxies (considering one for myself for next year's galaxy season) and the eq6r should handle it.

If you decide to make the move to a dedicated astro cam, go straight for mono as you already have a decent DSLR for OSC (maybe mod it in the interim?).

When you're looking at cameras, try to match the pixel size to the telescope(s) to get the optimum sampling rate for your typical skies. I follow  the general advice of others on this forum that there's no real benefit of going below 1"/px. Somewhere in the 1 - 2"/px range should get you good results. 

My only specific advice re: cameras is to take a pass on the 1600 (it's "old tech" now). If you're looking for a 4/3 sensor, go for the 294MM (or QHY equivalent) - higher QE, larger full well depth, greater dynamic range (unless you use it at some weird gain), lower dark current (not that that really matters given that dark currents are so low with either camera they are of no real consequence), and finally, no microlensing artifacts on bright stars. Basically there's nothing not to like 😁

For APS-C size, the recent IMX571 based mono astro cameras seem to be getting good press on the forums.

Good luck with your purchasing decisions!

[powerlord]

thanks for advice. And NEQ6 vs EQ6-r - for my application do you thing the 250 quid more is worth it for the belt drive of the R or will it be wasted on me or not required with ASIAIR compensating for backlash anyway, etc do you reckon ?

 

[Clarkey]

8 hours ago, The Lazy Astronomer said:

take a pass on the 1600 (it's "old tech" now).

I would agree with this. I got a 1600 last year and although there is nothing wrong with it, the performance of the 294 is definitely better - in particular the higher QE.

[powerlord]

1600 wise - there's one on ebay that might go cheapish is all... I mean it  might not - 2 days to go.

[Clarkey]

 

5 minutes ago, powerlord said:

1600 wise - there's one on ebay that might go cheapish is all

I wouldn't rule out a 1600 second hand if you can get a good deal. Yes, the 294 is better but the 1600 will still give excellent results. In a year or two the 294 with be 'old tech' too.

Edited April 26, 2021 by Clarkey
Gibberish

[powerlord]

update: ordered EQ-R PRO from FLO today. July earliest delivery 😞 . but I can wait - will keep learning with what I've got in the meantime. Next job is to collimate the 200p and try to get used to the thing.

 

[The Lazy Astronomer]

22 minutes ago, powerlord said:

update: ordered EQ-R PRO from FLO today. July earliest delivery 😞 . but I can wait - will keep learning with what I've got in the meantime. Next job is to collimate the 200p and try to get used to the thing.

 

Excellent choice 👍

Sure, it's a long wait, but you'll still have a good few months to get everything playing together nicely for a good winter's imaging. 

[ollypenrice]

I spent about 2 hours setting up, and trying to get the guiding tuned, and mostly I was getting RMS error of less that 2 degrees, with most of that being DEC (I assume my PA wasn't as good as I thought). I shot 60 lights at 180 seconds iso1600. I shot darks, flats and bias.

I think this must be a mistake. A 2 degree guide error would be nearly eleven times greater than the apparent size of target itself, which is about 11 arcminutes across!

A well tuned EQ6, properly autoguided, should be able to achieve an RMS of about 0.5 arcseconds. That will support an image scale of twice that, so an arcsecond per pixel. You might get this straight out of the box on night one, but don't bank on it. This means that there is little point in building up a system which tries to resolve at less than 1"PP. Even that might be pushing it if your seeing is not excellent. (Note, seeing, not transparency.) So, for galaxies other than M31, M33 and M101, aim for something like an arcsecond per pixel and you are likely to be aiming for the possible. This game is hard enough without aiming for the impossible.

This is a useful calculator: https://www.12dstring.me.uk/fovcalc.php

Olly

 

[powerlord]

thanks Olly, so you're saying for my skymax 102 and 6d - I'm at the boundary already then. add a barlow and it's too much for the guiding ? that's a pity - not a lot of pixels to play with. 😕

 

[The Lazy Astronomer]

1 hour ago, powerlord said:

thanks Olly, so you're saying for my skymax 102 and 6d - I'm at the boundary already then. add a barlow and it's too much for the guiding ? that's a pity - not a lot of pixels to play with. 😕

 

Galaxies are very small (with a couple of exceptions). Unless you have exceptional skies (and probably a £10k+ mount), I very much doubt that going below 1"/px will net you better images. Embrace the wider FOV and enjoy it! 😁

[michael8554]

On 25/04/2021 at 20:00, powerlord said:

I was getting RMS error of less that 2 degrees, with most of that being DEC (I assume my PA wasn't as good as I thought).

I expect you meant 2arcsecs, not degrees ?

Dec drift is due to PA error, but poor Dec guiding will be down to Dec Backlash, Dec balance, and PHD2 settings.

It sounds like you want to spend money instead of gaining experience.

Read some of the PHD2 Help and How To guides in the Help menu.

Michael

[powerlord]

I don't have access to PHD2 - only what ASIAIR PRO exposes. But yes, life is short - I'd rather get the kit I really want than waste it away struggling. 🙂